This invention relates to the chemical processing industry, more particularly the fermentation industry and most particularly fermentation tank sampling apparatuses.
In the fermentation industry there is a requirement for maintaining sterile conditions to avoid contamination of the product by, for example, undesired microorganisms. The sterilization requirement applies to fermentation feed lines, water lines and even the sampling valves. Sampling valves are merely output valves connected to fermentation tank useful for taking samples in order to follow the progress of the fermentation reaction.
Although a sterilizing steam line is connected to a sampling valve, maintaining sterile sampling valves is particularly difficult. When the valve is closed the outside of the end of the valve (which may have a further nipple attached) is not in contact with the sterilizing steam. Alternatively, when the valve is open the reduction in pressure lowers the steam temperature to sub-optimum levels (e.g., 250.degree. F. (121.degree. C.) to 210.degree. F. (99.degree. C.). Typically, the sampling valves are left open to continuously bleed steam in an effort to maintain as sterile conditions as possible at the sample valve. These open sample valves (essentially open steam lines) result in a wasteful release of steam. The continuous steam venting also compromises work conditions. Finally, the steam venting results in a continuous dripping of condensate that can compromise working conditions.
Thus, there is a continuing need and a continuing search in this field of art for alternative fermentation tank sampling valve apparatuses.